fix: preserve metadata on batch inlined responses

[volkan]

The SDK’s InlinedResponse type in types.go does not define a Metadata field, even though the REST InlinedResponse message has metadata alongside the response/error union. With this fix we will be able to batch

• Add Metadata field to InlinedResponse to match Batch API schema.
• Update inlinedResponseFromMldev to copy metadata, and still convert response / error, so per-request metadata is retained when reading batch jobs.

// Create InlinedRequest with metadata for result matching
		inlinedRequest := &genai.InlinedRequest{
			Model:    req.Model,
			Contents: []*genai.Content{content},
			Metadata: map[string]string{
				"product_id": fmt.Sprintf("%d", req.ProductID), // Store product ID for result matching
			},
		}

Response contained metadata:

With this change we will be able to get metadata to match jobs easily.

[volkan]

Hello @Sivasankaran25 any update on this?

[Sivasankaran25]

Hello @Sivasankaran25 any update on this?
Thank you for your contributions. The PR is currently under review.

[volkan]

Hello @Sivasankaran25
Any update about this PR?